A ball joint separator tool , may stop the shaft from spinning to remove the nut? A gas axe will work.. Sawzall with metal cutting blade?

 

If lower, jack up the control arm. If upper, use a pry bar to apply pressure.

 

Run a ratchet strap around the upper and lower control arms to force the ball joint stud into the spindle.

 

So I was roughly on the right path with trying to force the stud into the taper to hold it from spinning. Thank you gentlemen for the assistance @Lightspeed Mike and @autosportracing

 

@Lightspeed Mike worked out well for me. Was home during lunch and I jacked up the lower control arm, no issues getting the nut tightened. Broke out the pryin' bar and pulled down onto the upper and same deal. Thank you for the tip sir, learned something.

 

If the ball joint separator doesnt work, use a 1/8" drill and a chisel and split the nut. Usually have to drill 2-3 holes and one or two snacks in the chisel

A cut-off wheel is magic here (not the brittle Dremel stuff, but a 2" cookie wheel in the die grinder)

 

my situation was the re-assembly. Thank you for the additional information if I ever run into issues on the disassembly on the future.

 

In desperate case you can cut a slot in the very end and hold it with a screw driver while you tighten the nut. But ya gotta be careful not to burr the threads

 

SOmetimes manufactueres drill the cotter hole and bur up the threads. IF, you can't thread the nut on with your fingers all the way to the bottom you need to clean them up and your "spinning stud of death" won't be an issue.